Histo-blood group antigens and secretor status have been associated with susceptibility to Norovirus infections, which suggests that antibody prevalence and titer might correlate with these phenotypes. Plasma samples (n = 105) from Swedish blood donors that had been genotyped for secretor (FUT2) and Lewis (Le; FUT3) genotypes and phenotyped for ABO and Le blood groups were analyzed for immunoglobulin G antibody prevalence and titers to norovirus genogroup (GG) II.4. The results showed that nonsecretors () and individuals not only had significantly lower antibody titers than did secretors (P<.0001) and individuals (P<.0002) but were also significantly more often antibody negative (P<.05). Antibody titers in secretors were not significantly different between individuals of different Le (FUT3) genotypes or different ABO phenotypes. Nonsecretors and individuals are significantly less prone to be infected with GGII noroviruses. This new information extends previous knowledge and supports the hypothesis that nonsecretors are relatively but not absolutely resistant to norovirus infections.